Adding USB or internal HD - which is best option?
 

Hi,
I'm running Zenwalk 2.2 on my machine but I'd like to have another hard disk to use for testing other distros without impacting on Zenwalk, which is running perfectly after some initial tweaking.
My question is, which is the best option in terms of security/stability/ease of installation and configuration - adding a USB external drive or an internal one?
I suppose there'll be a speed/transfer issue with a USB drive?
Also, I'm assuming I'll have to edit the LILO config in my Zenwalk installation so the bootloader 'sees' the new drive and gives me the option to boot it?
I understand the process of making new partitions and file systems on the new drive, but do I also need to have another Swap partition on it?
Lots of questions, I know, but any help would be gratefully received.
Cheers,
Steve

if you don't mind opening up the case and inserting the drive, then i suggest internal (costs less, and less clutter on your desk too).